Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention is directed generally to an apparatus for a saw. More particularly, the present invention concerns an apparatus for a scroll saw that enables the parallel arms to move substantially independently of each other and that includes a retaining mechanism for one of the parallel arms. The present invention also relates to a drive mechanism and visual speed indicator that provides increased torque, a wide range of cutting speeds and allows for the visual determination of the speed of a saw blade.
2. Description of the Background
One type of conventional scroll saw has two parallel arms which are fixedly connected to each other at one end by a rear link. Each parallel arm also has a free end between which a saw blade extends and is connected thereto. The lower parallel arm is connected directly to a motor that moves the lower arm and the saw blade in a reciprocating motion. Because the lower arm and the upper arm are fixedly connected to one another by the rear link, the lower arm forces the upper arm to move in a corresponding manner to that of the lower arm. The disadvantage to this type of scroll saw is that if the saw blade becomes disengaged from one of the parallel arms or the saw blade breaks, the upper parallel arm will continue to move because it is fixedly connected to the lower parallel arm and, as a result, the broken or detached blade may mar the workpiece. Furthermore, the parallel arms may move out of sync resulting in the saw being damaged.
Conventional saws, drill presses, planers, etc. also typically include a drive mechanism and speed control apparatus for controlling the speed of the drive mechanism. One type of drive mechanism and speed control device employed with a scroll saw comprises a drive motor that is directly connected to the lower arm for moving the arms in a reciprocating motion. A speed control is employed to regulate the speed of the drive motor. The speed control is manually operable by virtue of an on/off dial knob, wherein indicia representing speed measurements is displayed around the knob. In most scroll saw applications, the range of speed of the motor is generally between 400 revolutions per minute (rpm) and 1600 rpm. The user""s choice of motor speed is dependent upon the workpiece material and the type of cut is to be made. The disadvantage of this type of drive mechanism and speed control device is that the user is limited to a small range of speed which constrains the type of cut that can be made and the type of workpiece material that can be used. Furthermore, the dial setting, which is usually in small print, can be difficult for the user to read, especially during operation of the saw.
Accordingly, there is a need for a scroll saw that has arms that move substantially independently of one another and that isolates the movement of one of the arms if an arm becomes inadvertently disengaged from the saw blade or the saw blade breaks. There is another need for a drive mechanism and visual speed indicator that is easily observed during operation and that enables the saw to make various cuts on a variety of workpiece materials. There is still another need for a drive mechanism and visual speed indicator that can be easily observed and employed on a myriad of other driven devices, tools, etc.
The present invention provides an arm configuration for a saw having spaced apart arms with a blade extending between and connected to the free ends of the arms and a link member extending between and connected to the other ends of the arms, wherein the arm configuration is constructed to allow the arms to move substantially independently of one another.
The present invention provides a scroll saw having two parallel arms that move substantially independently of one another such that if the saw blade breaks or becomes disengaged from the upper parallel arm, the motion of the upper parallel arm may be stopped to prevent marring of the workpiece or damage to the saw. A link member extends between and connects the distal ends of the two parallel arms and a saw blade extends between and is connected to the proximate ends of the two parallel arms. The link member is pivotably attached to one of the two parallel arms and is slideably attached to the other of the two parallel arms.
The present invention also includes a mechanism that will retain the upper parallel arm if the upper parallel arm becomes disengaged from the saw blade or the saw blade breaks thus, preventing the upper parallel arm from marring the workpiece or damaging the arm configuration. The upper arm retaining mechanism can take the form of a hook-shaped member which is spring loaded and pivotally mounted adjacent is the upper parallel arm.
The present invention further provides a drive mechanism and visual speed indicator which allows for easy verification of the speed of the saw, increased torque and the ability to cut a variety of materials and make a variety of cuts. The drive mechanism and visual speed indicator may be a motor and drive pulley assembly having a transparent pulley cover, wherein the drive belt is highly visible. The user can verify the speed of the pulleys by comparing the position of the drive belt on the pulleys with a speed chart placed on the saw.
The present invention further provides the arm configuration to be sized and proportioned to comfortably maneuver and accept a large workpiece. The space between the two parallel arms of the scroll saw which accepts the workpiece is unobstructed and large enough to maneuver and accept a variety of sized and shaped workpieces.
The present invention further provides that the two parallel arms are made from a composite material. The composite material may be a composite fiber cloth material impregnated with polymer material, wherein the fiber cloth may be carbon fibers.
The present invention solves problems experienced with saws. Those and other advantages and benefits of the present invention will become apparent from the description of the preferred embodiments hereinbelow.